Crude oil produced from production wells often contains asphaltenes that form deposits that can cause plugging of production equipment and plugging of the near wellbore formation. It can be very difficult to remove these asphaltenes and to recover from a plugged formation. Asphaltenes are the heaviest and most polar components in crude oil and they often contain nitrogen, oxygen, sulfur and trace amounts of vanadium and nickel. Heavier oils contain much higher proportions of asphaltenes.
When the crude oil is produced from a well, asphaltenes begin to deposit out of the hydrocarbon and can plug the pipe or the formation.